Mayflies

In the Netherlands, there are at least 59 species of mayflies. The mayfly lives in fresh water as larvae (nymph). In the spring, it crawls out of the water and together theyÂ form large swarms of millions of flies. Because mayflies often only live from a few hours to a maximum of a couple of weeks, they have no mouth. The only thing that an adult mayfly is concerned about is reproducing.

The nymphs (also referred to as naiad) of the mayfly remain in the water from several weeks to years, depending upon the species and temperature. These larvae have three tail threads at the back of their body helping them to swim very quickly. Gills for breathing are located on the segments of their abdomen. The nymphs are herbivores and live off of algae and plants. What makes mayflies exceptional is that they molt another time between the nymph and winged adult stage. TheirÂ wings are functional but they are still sexually immature. This stage is called subimago and lasts several minutes to several days.

The pairing dance of adult mayflies begins during half-light. The males gather in large clouds above the ground. They undulate up and down to a height of eight to ten meters, letting themselves fall back down again. As soon as a female enters the cloud, she is pounced upon by the males. The quickest one clasps itself to the female with its long front legs. The pairing takes place before the pair reachesÂ the ground. The male has accomplished his task and dies. The female lays the eggs, usually by pushing her hind end into the water and releasing them.